摘要:This is an interpretative article for better understanding of trends in bioethanol, starting from the historical background of the primary energy requirements indicated in the 2nd IPCC Report. Methods for production of bioethanol from biomass are briefly described with emphasis on the advantages of enzymatic decomposition of biomass, especially soft cellulosic biomass. The energy efficiency of bioethanol production from soft biomass is computed using results obtained from a model study in which the ethanol raw material was cut grass from golf courses. The role of mega-cities as producers of bioethanol and related new energy forms are also discussed.